In the figure, ABC is parallel to DEF and DC cuts ∠BDE equally. Given that ∠ABD = 50° and ∠BGC = 103°, find
- ∠a
- ∠b
(a)
∠ABD = ∠BDE (Alternate angles)
∠a
= 50° ÷ 2
= 25°
(b)
∠BDG = ∠a = 25°
∠b
= 103° - 25°
= 78° (Exterior angle of a triangle)
Answer(s): (a) 25°; (b) 78°